With conventional clock generators of this kind, a voltage-controlled oscillator is typically provided as an adjustable oscillator. A low-pass filter is additionally connected to the voltage-controlled oscillator from a phase comparator. In turn the output of the voltage-controlled oscillator is fed back to an input of the phase comparator to achieve a phase-locked loop (PLL).
A disadvantage in this respect is that a large number of external components is needed. In addition, the analog functional units employed--such as phase detector, low-pass filter and voltage-controlled oscillator--have a relatively complex configuration. The current consumption of such an analog clock generator is also relatively high.
An object of our invention is to create a clock generator together with a suitable phase comparator of the aforementioned kind which ensures reliable operation despite its simpler configuration and relatively low current consumption, enabling a more precise adjustment of the frequency.